Mechanically Strong Electrically Insulated Nanopapers with High UV Resistance Derived from Aramid Nanofibers and Cellulose Nanofibrils

Abstract

Aramid nanofibers (ANFs) have great potential for civil and military applications due to their remarkable mechanical modulus, excellent chemical reliability, and superior thermostability. Unfortunately, the weak combination of neighboring ANFs limits the mechanical properties of ANF-based materials owing to their inherent rigidity and chemical inertness. Herein, high-performance nanopapers are fabricated by introducing a tiny amount of cellulose nanofibrils (CNFs) to serve as reinforcing blocks via vacuum filtration. As a result of the formation of nanosized building blocks and hydrogen-bonding interaction of CNFs, the resultant ANF/CNF nanopaper yields a record-high tensile strength (406.43 ± 16.93 MPa) and toughness (86.13 ± 5.22 MJ m −3 ), which are 1.8 and 4.3 times higher than those of the pure ANF nanopaper, respectively. When normalized by weight, the specific tensile strength of the nanopaper is as high as 307.90 MPa•g −1 •cm 3 , which is even significantly superior to that of titanium alloys (257 MPa•g −1 •cm 3 ). The ANF/CNF nanopaper also possesses excellent dielectric strength (53.42 kV mm −1 ), superior UV-shielding performance (≥99.999% absorption for ultraviolet radiation), and a favorable thermostability (T onset = 530 °C). This study proposes a new design strategy for developing ultrathin ANF-based nanopapers combined with high reliability and thermostability for application in highend electrical insulation fields, such as 5G communication, wearable electronics, and artificial intelligence.

Enhancing Bioinspired Aramid Nanofiber Networks by Interfacial Hydrogen Bonds for Multiprotection under an Extreme Environment

“…The excellent mechanical properties thanks to chitosan demonstrated in uniaxial tensile experiments were also confirmed during crack propagation (Figure S14). It is worth mentioning that the addition of supersaturation led to agglomeration in the fiber network, which weakened the mechanical properties. , The Lagrange strain fields in the Y direction (ε yy ) for C-ANF networks of 7.5 wt % chitosan in the crack propagation process were calculated (Figure c). The 2D-DIC algorithm used in this paper was based on the subregion deformation.…”

A flexible, robust and multifunctional montmorillonite/aramid nanofibers@MXene electromagnetic shielding nanocomposite with an alternating structure for enhanced Joule heating and fire-resistant protective performance

“…On the other hand, the strong interfacial interaction between ANFs and MMT as well as the mechanical interlocking network among ANFs in AT layers led to the crack of the “pull-out” mode of fibers. 41 Interestingly, hierarchical zigzag cracks could absorb lots of fracture energy in the crack propagation process, and the “pull-out” process of ANFs also absorbs vast energy and effectively prevents the cracks propagation. 42 This results in the significant improvement of strength and toughness of the AT3@MX2 nanocomposite.…”

Preparation of high breakdown strength meta‐aramid composite paper reinforced by polyphenylene sulfide superfine fiber

“…The other way is introduction of nanofibers into the paper. [22][23][24] Yang et al [23] found that para-aramid paper containing 6 wt% para-aramid nanofibers had a 44.1% higher breakdown strength than the original paper. Although these methods have improved the performance of aramid paper, there are still some unavoidable problems.…”